In known ski bindings, the rear jaw is usually movably guided on a carriage in a direction parallel to the longitudinal axis of the ski and is initially tensioned toward the boot by a pressure spring. During insertion of the ski boot into the binding, the rear jaw is moved toward the tail of the ski against the force of the pressure spring. This assures a secure holding of the ski boot in the ski binding and compensates for possible inexactnesses during the adjustment of the binding to the ski boot size. However, this construction has the disadvantage that a further shifting of the rear jaw occurs during skiing through depressions, namely when the ski is flexed, which results in a change in the release values of the spring biassed components. This occurs on the one hand due to the increased friction between the ski boot and the jaw. On the other hand, the pressure spring and the release spring which determines the release force are coupled primarily with one another, so that the release values are increased.
Therefore, rear jaws have been developed, in which the release force is independent of the shifting movement of the rear jaw. However, this solution is not satisfactory because the increase of the release force for both the front jaw and the rear jaw, due to the increased frictional engagement of the ski boot with the jaws, cannot be compensated for.
A further problem of such ski bindings consists in many falls occurring when the skier's body is positioned close to the ski, namely when the skier is in a squatting position to minimize the air resistance. In skiing toward an obstacle in this position, for example a snow hill, a relatively small release moment is created. The release values of the rear jaw, which are adjusted to the normal upright position of the body, are thus not attained and the ski boot cannot release from the ski binding.
Thus it has become known to support the front jaw on a carriage which is movable in longitudinal direction of the ski in order to reduce the danger of injury during frontal falls. The front jaw is moved forwardly against the force of a spring during insertion of the ski boot into the binding. When the skier's ski hits a frontal obstacle, the front jaw will slide further forwardly so that the ski boot can be removed from the heel mounting. However, this solution cannot be identified as an optimum solution, because a clearly defined position of the tip of the boot is not determined, or a guiding of the ski is very inexact, because due to the practically floating support of the ski boot, the position thereof will constantly change during skiing.
Therefore, the basic purpose of the invention is to provide a ski binding which permits as usual a fixed and exactly determined position of the ski boot on the ski and avoids the disadvantages during skiing or during frontal impact with an obstacle, namely avoids an increase in the release force of the ski binding components.
The invention provides for this a stop which is associated with the rear jaw to limit the path of movement of the rear holding part of the rear jaw in a direction toward the tail of the ski, and the front holding part or in a conventional manner the front jaw is movably guided against a spring force in a direction toward the tip of the ski.
The adjustment of the ski binding can therewith be selected such that the ski boot effects in inserted condition a shifting of the rear jaw or of the rear holding part until it engages the stop. Thus the ski boot remains even during a flexing of the ski in a fixed position because in this case the rear jaw is stationarily supported at the stop and the front jaw is moved. It is particularly preferable if the front holding part or the front jaw is initially tensioned against a stop toward the tip of the ski boot.
The pushing force of the front and the rear jaw is dimensioned such that preferably the spring force of the rear jaw, which spring force acts toward the heel of the ski boot, is smaller during movement of the rear jaw in the region of its stop than the spring force of the front jaw, which spring force acts toward the toe of the ski boot.
In a preferable exemplary embodiment of the invention, an abutment for at least one release spring of the rear jaw, which is constructed as a release jaw, is connected to a base plate which is secured or fixed to the ski, wherein the spring tension of the release spring is reduced during a shifting of the rear jaw or of the holding part toward the boot.
This construction has the advantage of, when the skier hits an obstacle, moving the front jaw and the rear jaw toward the tip of the ski to effect a relaxing of the release spring of the rear jaw, namely the release force of the same is reduced. Thus, already a substantially smaller forward tipping moment of the skier is sufficient to release the ski boot. This is an important advantage particularly during skiing in the squatting or streamlined position or during falls in the squatting position.
It is furthermore preferred if an abutment member for at least one release spring of the front jaw, which is constructed as a release jaw, is arranged on a base plate which can be secured or fixed to the ski, wherein the spring tension of the release spring is reduced during shifting of the front jaw in a direction toward the tip of the ski.
Thus this effect can also be achieved for the front jaw during a release which occurs typically for twisting falls or torsional stresses on the leg.
The inventive measures can practically be applied to all common front and rear jaws or release systems.
The invention will be discussed more in detail hereinafter with reference to one exemplary embodiment and referring to the figures in the drawing; however, the illustrated structure is not to be limiting.